Signaling apparatus for telephone-switchboards.



PATENTED JUNE 14, 1-9'04.

.P. R. MABERTY A J. L. MOQUARRIB. SIGNAL-ING APPARATUS FOR TELEPHONE SWITGHBOARDS.

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- PATENTED JUNE 14, 1904. P. R. MOBERTY & J. L. MOQUA'RRIB. SIGNALING APPARATUS FOR TELEPHONE SWITCHBOARDS.

APPLICATION FILED FEB. 20, 1902.

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NVENTRS: FRANK l?. MBE/YTY, JAMES L. MCQUARRIE,

ATTURNEY.

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UNITED Y STATES Patented June 14, 1904.

PATENT OFFICE.

FRANK R. MCBERTY, OF EVANSTON, ANI) JAMES L. MCQUARRIE, OF CHICAGO, ILLINOIS, ASSIGNORS TO WESTERN ELECTRIC COMPANY, `OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SIGNALING APPARATUS OR TELEPHONEFSWITCHBOAFIDS SPECIFICATION forming part of Letters Patent No. 762,336, dated June 14, 1904. Application tiled February 20, 1902. Serial No. 94,880. (No model.)

T0 all whom, t may concern:

Be it known that we, FRANK R. MGBERTY, residing at Evanston, and J AMES L. MCQUARRIE, residing at Chicago, in the county of Cook and State of Illinois, citizens .of the United States, have invented'a certain new and useful Improvement in SignalingApparatus forTelephone-Switchboards, of which the following is a full, clear, concise, and exact description. Our invention relates to a signal device to be applied more particularly to telephoneswitchboards.

Our object has been primarily to producea simple automatic device which would display a signal when a subscriber first transmitted a call for connection,Y then efface this signal when the operator answered the call by Plugging into the spring-jack of the line, and subsequently display a signal to indicate a call for disconnection when the conversation is iinished.

The fundamental idea of our invention is the adapted for successive actuation, to cooperate in the control of signaledisplaying mechanism which is adapted to give alternative indications, each part beingcapable of occupying either one of two Yalternative positions and adapted when moved independently of the other part to effect a change of the signal indication. One of the parts may serve to actuate the signal-indicating device, while the other part serves as a controlling element to determine the operative relation between the first part and the signal-inc'licating device, so that theindependent actuation of either part will eect a change of the signal indication, the character of such changeA being dependent upon the position of the part which is not ac. tuated. In the preferred embodiment of our invention as applied to a switchboard-signal one of the moving parts is the armature of an annunciator-magnet, said armature carrying a target, and the other part is ashield having a hole in which the target is adapted to be displayed, this shield being movable through the agency of mechanism which is actuated by the insertion of an operators switch-plug in a spring-jack. In this device the excitement of the line-annunciator magnet causes the target to be displayed in the opening of the shield. Then when the answering-plug is inserted in the spring-jack the shield is moved so that the opening therein no longer registers with the target, but registers with the position originally occupied by the target, the signal being thus eifaced. When the annunciator-magnet is denergized, as at the termination of a conversation, the target is moved back to its original position and is displayed in the opening of the shield to constitute asignal for disconnection. The operator Vresponds to this by pulling out the plug, vwhereupon the shield resumes its normal position, concealing the target. The movement of the target independent of the shield will thus eifectra change of the signal indication, and inthe same way if the target is maintained stationary and the shield moved the Y i signal will also be changed. The character mechanical association of two moving parts of the signal indication is dependent uponthe relative positions of the two parts rather than upon the position of either part considered by itself, a given signal indication being produced by the coincidence of both the moving parts in either of their alternative positions.

- We Vwill describe our invention more particularly by reference to the accompanying drawings, in which- Figure 1 is a diagram illustrating two telephone-lines extending from substations to a central-oiice switchboard, with the operators switching apparatus for temporarily uniting lines, the system being organized and equipped for automatic signaling in accordance with our invention. Fig. 2 is a side elevation of the combined spring-jack .and signal device.A Fig. 3 is a similar view showing the armature of the line-signal magnet attracted to display the target, with a plug in position to beinserted in the spring-jack- Fig. 4 is a sectional view showing the plug inserted in the yspring-jack and the signal'eiaced. Fig. 5 is a view similar to Fig. 4, with the armature of the signal-magnet retractedto display the disconnect-signal; and Fig. 6 shows the front of a strip of four of the combined annunciators and spring-jacks.

Similar letters and numerals of reference are used to designate the same parts wherever they are shown.

Referring first to Fig. l, each telephoneline extends in two limbs l Q from the usual substation apparatus to the central ofiice switchboard, where the conductors are led through the contacts of multiple spring-jacks to the poles of a central battery L. The winding of the annunciatormagnet a is interposed in the circuit of conductor 52, which is connected to the free pole of the battery, and an impedance coil is interposed between the grounded pole of said battery and the conductor l. The apparatus at the substation is of the usual' character and includes an ordinary gravity ltelephone-switch c, which is adapted automatically to close the bridge of the line-circuit containing the telephones when the receiver is-taken for use. rlhe answeringjack of each telephone-line at the central office is associated with the annunciator, t'nese two `type known as vanswering-jack'are connected with the line conductors through the switcli-eontacts of the line-jacks, so that when any line -jack is plugged into the line-battery, answering-jack, and line-signal will be cut olf. The operator is provided with the usual pairs of plugs for temporarily connecting lines together,. the plugs of each pair being united by link conductors 4t 5- of a plug-circuit.` A central battery is shown connected in a bridge of the f plug-circuit between the windings of a repeating-coil in the usual manner. VVhile,for clear- V'ness ofilliistration, we have shown the battery in the plug-circuit separate from the line-batteries of the different teleplione-lines, it is understood that in accordance with the usual practice a single central battery may be employed, which may be connected as indicated. A supervisory signal (l is shown included in the conductor 5 between the free pole of the battery and the ring-contact of the callingplug, so as to be responsive to the movement of the telephone-switcli at the substation of the line, `to which the calling-plug may be connected in response to a call originated at some other station. This supervisory signal forms no part of our present invention, its structure and operation being well known in the art. It will be seen that the line-annunciatormagnet e of each line is in the path of current from the central battery b, controlled by the telephone-switch c at the substation of the line. l/Vhen the subscriber desires a connection with some other line, he sends in a call by removing his telephone from its switch, thus closing the line-circuit and causing current to flow through the line-annunciator magnet a. A signal controlled by this magnet is displayed, as will hereinafter be more fully explained, and the operator responds to the call by inserting her answering-plug ein the answering spring-jack f of the' line in question, this spring-jack being immediately below the annunciator. Having learned the number of the called party, the operator, after making the usual busy test, (which need not here be described) if the line wanted is free inserts the calling-plug in one of the line sprink-jacks of that line and transmits a callsignal by means of her ringing-key in the u'sual way, whereupon conversation between the substations of the two lines may be had, the lines being connected through the link conductors of the flexible cord-circuit which unites the two plugs. When the conversation is finished, the disconnect-signal of the called subscriber may be indicated by the supervisory signal d in the cord-circuit, and the discoiinect-signal of the calling party will be indicated at his line-annunciator e.

We will now proceed to describe more particularly the structure of our improved an nunciator or signal device, referring to Figs. 2 to 6. The answering spring-jack itself is of a well-known type, comprising the linesprings'fj, which are connected with the limbs 1 2 of the telephone-line, respectively,

and the test ring or tliimble f3, which forms I the terminal of a busy-test circuit 3, well known in the art. The plug e, which is intended to be inserted in the spring-jack of any line to make connection therewith, is of a type well known in the art, having tip, ring, and sleeve contact-pieces e @2 e3, which are adapted to register with the short and long line-springs and the test-thimble,respectively, of the sprink-jack. Plugs of this kind as now constructed usually have an annular enlargement or bead e* between the tip and ring contact-pieces to take up the Wear. The electromagnet e of the annunciator is mounted lupon the insulating-strip which carries the contact-pieces of the spring-jack. The armature of the magnet is a soft iron-bar a', secured to a strip of spring metal a2, which is fastened at the rear of the magnet and extends forward in the line of the core, the strip being bent down at the forward end to form a target a". The spring-mounting of the armature normally holds the same in an inclined position, as shown in Figs. 2 and 5; but when the magnet a is excited the armature is drawn down against the two pole-pieces at the extremities of the core, as shown in Figs. 8 and 4. Coperating with the target ai", which is moved by the armature a', we providea shield e", which occupies the space be- IOO IIO

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tween the target as and the slotted plate or grating Q, which forms the face of the annunciator. lThe shield at may be formed by the upturned end of a strip of spring metal a5, which lies along the top of the insulatingblock carrying the contact-pieces of the spring'- jack. This spring-strip ai' is fastened to the insulating-head of the annunciator-magnet at the rear end; but the forward end, carrying the shield af, is free to move. A portion of the spring-strip over the ends of the linesprings is cut out and bent down to form a tongue al, which is adapted to be engaged by the bead e'1 of any plug which may be inserted in the spring-jack. As the plug is inserted the tongue a rides up on the bead e* of the plug, and the free end of the spring a5 is raised, moving the shield relatively to the target (t3, which lies behind it. As shown in the drawings, the shield at is provided with three horizontal openings or slits, through which the face of the target-piece o3 may be seen. The face of this target-piece is painted with alternate horizontal stripes of white and black. When the parts are in their normal positions, as shown in Fig. 1, and as shown also at I at the extreme left of Fig. 6, the white stripes on the target a3 are behind the shield, and the black stripes are seen through the slits in the shield. The face of the shield may be painted black, so that the annunciator in its normal condition will show simply black. Vhen the magnet of the annunciator is eX- cited; as when a call is transmitted from the substation, the armature a' is drawn down and the target als moved to the position showny in Figs. 3 and 4, displaying the white stripes of the target behind the slits in the shield r, as shown at II in Fig. 6. When the operator responds to the call by inserting her plug' e in the spring-jack immediately below the annunciator which has shown the signal, the shield a* is moved up, so that the openings or slits therein no longer register with the white stripes of the target, but register instead with the positions which the white stripes occupy in the normal condition of the annunciator, so that the black stripes are displayed in the openings of the shield. The signal is thus effaced, as appears at IH in Fig. 6,4

the annunciator remaining in this condition until the calling party replaces his telephone on its hook, and so deprives the annunciatormagnet of current. When the magnet is thus denergized and allows its armature to fall back, the target a3 rises to its normal position, so that the white stripes again register with the openings in the shield, displaying a disconnect-signal, as shown at IV in Fig. 6. rlhe operator responds to this disconnect-signal by removing the plug, whereupon the spring a5 resumes its normal position, moving the shield down to conceal the white stripes of the target.

In the diagram Fig. l we have for clearness shown a small target a3, carried by the armature of the annunciator-magnet, and a shield with a single opening instead of several openings, behind which' the target is adapted to be displayed. l

, It will be apparent that the ideasherein set forth may be embodied in structures which may differ widely in form,and we do not, therefore, desire to be understood as limiting ourselves to the particular annunciator device shown; but,

Having thus described one embodiment of our invention, we claim- 1. The combination with two moving parts Y mechanically associated with one another and adapted for successive actuation, of a signal `adapted to give alternative indications controlled by said two parts jointly, either of said parts when independently actuated being f adapted to change the signal to an alternative indication and to restore the signal upon a subsequent independent reverse actuation.

2. The combination with two moving parts each adapted to be given alternative positions, of a signal controlled jointly by said parts and adapted to give alternative indications, a given signal indication being dependent upon the coincidence of said moving parts in either one fof their alternative positions, substantially as set forth.

3. The combination with a target and means for moving the same from one to the other of two alternative positions, of a shield having an opening in which the target is adapted to be displayed, said shield being movable independently of the target to register with either of the alternative positions thereof.

4. The combination with a plug and springjack switch, of an annunciator-magnet and an armature therefor carrying a target, and a shield havingan opening in which the target is adapted to be displayed, said shield being movable by mechanism actuated in the insertion and withdrawal of the plug, said target and shield cooperating in the indication of visual signals.

5. The combination with a moving part adapted to be given alternative positions, of a signal controlled in the movement of said part, said signal being adapted to give alternative indications according to the position of said part, an alternative controlling device adapted to reverse the signal indication produced by either position of said moving part, andmeans for actuating said controlling device, whereby a change of the signal indication may be produced by an independent movement of either the first-mentioned moving part or the controlling device, as set forth.

6. The combination with a telephone-line extending from a substation to a central office, of a source of current connected therewith, a switch at the substation controlling the fiow of current in the line, an electromagnet at the central ofce responsive to the current so con- IOO IIO

trolled, an armature for the magnet, a signal controlled by said armature adapted to give alternate indications according to the position thereof, a plug and springjack switch for making connection with the line, and a controlling device actuated in the operation of the plug and spring-jack Switch, adapted to reverse the signal indication given in either position ofthe magnetarmature, whereby the signal indication caused by the initial attraction of the magnet-armature is etl'aced in making connection with the line, and a signal is subsequently displayed during connection when the magnet-armature is retracted.

7. The combination with a telephone-line extending from a substation to a central oiiice, of a source or' current connected therewith, a switch at the substation controlling the How of current in the line, an ann unciator-rnagnet at the central oiice responsive to the current so controlled, a target adapted to occupy either one of two alternative positions, said target being moved by the armature of the annunciatormagnet, a spring-jackor the line, a plug and plug circuit for making connection therewith, a movable shield having an opening in which the target is adapted to be displayed, said shield being movable so that the opening therein will register with either one of the alternative positions of the target, and mechanism actuated by the insertion and withdrawal of the plug for moving the shield, substantially as set forth.

In witness whereoil we hereunto subscribe our names this 4th day of January, A. D. 1902.

FRANK R. MCBERTY. JAMES L. MCQUARRIE. Witnesses:

.EDWIN H. SMYTHE,

FREDERICK A. VVATKINs. 

